Around 5:20 pm (local time) on 9 March 2012, a small pyroclastic flow travelled down the western flanks of Soufriere Hills Volcano down Spring Ghaut. This small pyroclastic flow went about 1 kilometre to the west towards Plymouth before the ash dissipated in a small ash cloud, which rose about another 4000 feet and towards St. Georges Hill out to sea. The event was caught on the camera on Garibaldi Hill (pictured above) as well as on the thermal camera.
MVO’s seismic monitoring network also recorded the event. To the left is a plot of the seismic signal generated by the flow, as recorded from the seismometer at Fergus Ridge. MVO’s seismometers record pyroclastic flows as they occur. The shaking recorded by the seismometers is caused by the material in the flow colliding with the ground as it travels.
There were no precursors to this event. Although activity has generally been low, this event clearly illustrates that Soufriere Hills Volcano is still an active volcano and that pyroclastic flows can occur at any time with little to no warning.